In March of 1953, Lavrenty Beria united the MVD and MGB[?] into one body, the MVD. Within a year, Beria was executed and the MVD was split up. The reformed MVD retained its internal security functions while the new KGB took on external security functions. The KGB was subordinated to the Council of Ministers. On July 5, 1978 the KGB was renamed the "KGB of the USSR" with the KGB Chairman given a seat on the council.

Tasks and Organization
Its tasks were external espionage, counter-espionage, liquidation of anti-Soviet and counter-revolutionary formations within the USSR, and guarding the leaders of the party and state. Unlike Western intelligence agancies, the KGB was (theoretically) not interested in learning enemy intentions, only their capabilites. Intentions were political decisions based on Marxist theory and the personal whims of the leadership.

In its espionage role, the KGB was mostly reliant on human intelligence, unlike their western counterparts, who relied far more on imagery intelligence (IMINT) and signals intelligence. Using ideological attraction, the Soviets were successful in recruiting a number of high level spies. Most notable are the KGB successes in gathering US atomic secrets, and the Cambridge Five, especially Kim Philby in the UK. This ideological method of conversion failed after the 1956 crushing of the Hungarian uprising. Instead, the KGB was forced to rely on blackmail and bribery for most of its defectors. This still achieved notable succeses, such as CIA mole Aldrich Ames and FBI mole Robert Hanssen, but far fewer than earlier.

Ethel and Julius Rosenberg were executed by the United States for providing information on the US's atomic programs to the KGB.

James Jesus Angleton[?], head of CIA counter-intelligence, reportedly lived in deathly fear that the KGB had moles in two key places: CIA counter-intelligence and FBI counter-intelligence. With those two moles in place, the KGB would have control or awareness of all U.S. efforts to catch KGB spies, and could protect their assets by safely redirecting any investigation that came close, or at least provide sufficient warning; also, counter-intelligence had the job of vetting foreign sources of intelligence, so moles in that area were in a position to give a stamp of approval to double agents against the CIA. With the capture of Aldrich Ames and Robert Hanssen, it appears that Angleton's fears, deemed paranoid at the time, were well-grounded.

Organization
The KGB was organized into directorates. Some of the main directorates were:

The First Chief Directorate (Foreign Operations) was responsible for foreign operations and intelligence-gathering activities.

The Second Chief Directorate was responsible for internal political control of citizens and foreigners within the Soviet Union.

The Third Chief Directorate (Armed Forces) controlled military counterintelligence and political surveillance of the armed forces.

The Fifth Chief Directorate also dealt with internal security. Originally created to combat political dissent, it took up some of the tasks previously handled by the Second Chief Directorate.

The Seventh Directorate (Surveillance) handled surveillance, providing equipment to follow and monitor the activities of both foreigners and Soviet citizens.

The Eighth Chief Directorate was responsible for communications. It dealt with monitoring foreign communications and was also responsible for the cryptological systems used by KGB divisions, transmission to KGB stations overseas, and the development of communication equipment

The Ninth Directorate (Guards Directorate) provided guards for principal Party leaders and their families, and major government facilities in the Soviet Union.